Sonic signal generator



FIG. 1 is a perspective view of a sonic signal generator showing my _design;

FIG. 2 is a top plan view thereof;

FIG. 3 is an elevational view of one of the longer sides of the sonic _signal generator, the other longer side being identical as viewed; and,

FIG. 4 is an elevational view of one of the shorter sides of the sonic _signal generator, the other shorter side being identical as viewed. 

The ornamental design for a sonic signal generator, as shown. 